If it weren't for the medicine, Carroll would suffer more during the fall while doing his job. When Carroll mulches leaves, he stirs up leaf mold, triggering his allergy symptoms like a runny nose and itchy eyes.

Fall starts today, and though the new season brings colorful leaves, Halloween and Thanksgiving, it also brings the sniffles and sneezing that come with allergies.

The rankings looked at the 100 most populous metropolitan areas in the United States. They were based on an analysis of factors including pollen scores, the number of allergy medications used per patient and the number of allergy specialists per patient.

The main culprit in Chattanooga's poor ranking was medication usage, said Allergy Foundation spokeswoman Angel Waldron. High usage in the area may be caused by challenges in the environment and poor allergy-management plans, she said.

Many other Southern cities were listed in the top 20, including Knoxville, which was ranked first, and Memphis, which ranked 12th.

Dr. Marc Cromie, with Chattanooga Allergy Clinic, said the trend could be explained by the fact that ragweed season tends to be longer in warm climates because the plant doesn't die until it freezes.

Ragweed pollen and mold tend to cause allergies in the fall, Cromie added.

"Fall is the perfect storm for allergies and asthma," he said.

Mold in school buildings can be a problem when students and teachers return to school after being outside the buildings all summer, Cromie said.

Sheryl Rogers, health services coordinator for the Hamilton County Schools, said she also sees an increase in food and environmental allergies when children get to school.

Susan Raschal, an asthma and allergy specialist in Chattanooga, said people in the area may be taking medications because they have allergies that trigger asthma. She added that non-pollen factors such as respiratory irritants including pollution, cigarette smoke and gas fumes, seasonal differences and weather changes also may be causing people to take allergy medications.

"We want people to use as few medicines as possible," the physician said.

Despite the challenges for allergy sufferers in Chattanooga, Waldron said the solution is "not to pack up and move anywhere."

Cromie said that in addition to taking medications and using nasal sprays, people should avoid opening their windows and exercising outside in the morning. If medications don't work, Cromie suggested people seek out board-certified allergists who can give shots to boost immunity to allergies.

"There's no reason why people should be suffering this year," Waldron said.